Filed Under (Chevrolet) by admin on 10-09-2010
On customer comments of low heater output on 1989-91 J cars, before replacing a suspected defective engine cooling thermostat, proper diagnosis of the condition must be performed to avoid the possibility of a repeat repair. Follow “Diagnosis” as shown in Section 1A/1B of the appropriate Service Manual. After completing the diagnosis, use the following as a guide to the next corrective step: ^ If the diagnosis indicates a defective thermostat, refer to Section 6C for replacement. ^ If the diagnosis indicates a defective temperature control cable, refer to Section 1A/1B for replacement. ^ If the diagnosis indicates the temperature control cable is no longer “snapped” into its retainer, refer to “Temperature Control Cable Repair” in the 1991 Service Manual, Sections 1A/1B. ^ If the diagnosis indicates that the temperature control cable is out of adjustment, refer to the following procedure to repair. TEMPERATURE CONTROL CABLE ADJUSTMENT PROCEDURE Condition: Condition: Cause: Correction For Number: 1. “Spring back” off full “hot” temperature control position (or not attaining full “cold” temperature door position). 2. “Spring back” off full “cold” temperature control position (or not attaining full “hot” temperature door position). The temperature control cable “clip” needs adjustment. Refer to the illustration for correct gripping of the “clip” during adjustment. 1. Grip “clip” at module end of cable while pulling temperature control lever to “hot” position.